Both sickle cell anemia and beta-thalassemia are serious clinical disorders resulting from mutations affecting the adult beta-globin gene. Numerous epidemiological studies have suggested that increased production of fetal hemoglobin in sufficient quantities can ameliorate the clinical severity of both disorders. The purpose of this pilot study is to determine the range of responses to intravenous arginine butyrate as gauged by the increase in fetal hemoglobin prodution in patients with sickle cell anemia and beta-thalassemia syndromes.